Osirix lite software

T₂ transverse relaxation data were measured by a MesoQMR23-060H NMR analyzer (Suzhou Niumag Analytical Instrument Co., Suzhou, China). The permanent magnet was kept at 32 °C with a 0.5 T magnetic field strength. A Carr–Purcell–Meiboom–Gill (CPMG) sequence with parameters including 90° pulses, 180° pulses, and π-value of 21.00 μs, 42.00 μs, and 200 μs was used to collect the relaxation decay data. After removing the surface water, the sample was placed in the 60-mm-diameter tube NMR probe and measured under 10,000 echoes with four scan repetitions. The inversion of the CPMG decay data was performed using MultiExp Inv analysis software (Suzhou Niumag Analytical Instrument Co., Suzhou, China) to obtain the T₂ distributed curve as well as the relaxation parameters of different proton components.
MRI experiments were performed by the same MesoQMR23-060H NMR analyzer with spin echo (SE) imaging sequence. The scanning parameters of matrix size, field of view, and slice width were 256 mm × 196 mm, 100 mm × 100 mm, and 3 mm, respectively. The echo time (T_E) and repetition time (T_R) of the T₁ weighted image were 40 ms and 660 ms, respectively, while that of the T₂ weighted image were 40 ms and 3300 ms. The raw MRI images were processed using OsiriXLite software (v7.0.4, Pixmeo, Geneva, Switzerland) to obtain pseudo-color images and the corresponding intensities.

Trained analysts (one radiation oncologist, one radiologist) blinded to outcomes independently quantified total muscle CSA on an axial image at the level of the T8, T10, and T12 thoracic vertebral bodies under the supervision of board‐certified thoracic radiologists (F.J.F., C.P.H.). Analysts used semi‐automated threshold‐based segmentation (−29 to +150 Hounsfield units) as illustrated in Figure 2 and previously described.¹⁴ Analysts used OsiriX Lite software (version 11.0.3, Pixmeo SARL, Bernex, Switzerland) at MGH and the Syngo Volume tool (Siemens Healthineers) at HDB. Twenty‐five randomly selected subjects were assessed with both software packages to determine inter‐software agreement. Two additional sets of 25 randomly selected subjects (one set per institution) were compared with the same software to determine inter‐analyst agreement.

The transverse relaxation time (T₂) was measured by an MesoMR23-060V-I NMR analyzer (Suzhou Niumag Analytical Instrument Corporation, Suzhou, China) with a permanent magnet having resonance frequency 21 MHZ at 32 °C. The fish meat sample was placed on a 60 mm diameter sample chamber for LF-NMR measurement. The Carr–Purcell–Meiboom–Gill (CPMG) decay signal was collected with pulses of 90° and 180° at 26 and 52 μs. The τ-value was set 200 μs and the number of echoes (NECH) was 8000 which were recorded in a sixteen repetition with repetition time 4500 ms. The relaxation curves M(t) were fitted by the following equation: $\mathrm{M}(\mathrm{t})={{\displaystyle \sum }}_{\mathrm{n}=1}^{\mathrm{N}}{\mathrm{M}}_{0,\mathrm{n}}\exp \left(\frac{-\mathrm{t}}{{\mathrm{T}}_{2,\mathrm{n}}}\right)+\mathrm{e}\left(\mathrm{t}\right)$
where M(t) represents the residual magnetization at decay time t, M_0,n is the magnitude parameter of the n^th exponential, T_2,n is the corresponding transverse relaxation time constant, and e(t) is the residual error [10 (link)].
The MRI images of samples were acquired on a MesoMR23-060V-I NMR analyzer too. T₁ weighted images was recorded using spin-echo imaging sequence with field of view (FOV) of 100 mm × 100 mm, slice gap: 2.0 mm, slice width: 2.6 mm, offset slice: 26.4 mm, average: 2, phase size: 192 and read size: 256. The echo time (TE) was 20 ms and repetition time (TR) was 500 ms. OsiriXLite software (version 7.0.4, Pixmeo, Geneva, Switzerland) was used for analysis of the MRI images.